Cryptic cross-kingdom interactions: The impact of fungal parasitism on phytoplankton–bacteria interactions revealed via genome and transcriptome profiling

• Applicant: Isabell Klawonn, Ph.D.
• Subject Area: Organismic Interactions, Chemical Ecology and Microbiomes of Plant Systems ; Microbial Ecology and Applied Microbiology ; Oceanography
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 514207343

About half of the World’s primary production is attributed to microscopic phytoplankton in the aquatic biosphere. Phytoplankton are therefore the basis of aquatic food webs and they fundamentally impact carbon cycling and the composition of our Earth’s atmosphere. The growth of phytoplankton as well as crucial phytoplankton–bacteria interactions, however, can be distorted by fungal parasites, with unknown regulatory mechanisms on a molecular level. To resolve those mechanisms, we will use OMICS on two model pathosystems. The 1st phytoplankton–fungal parasite system is maintained in our laboratory and its genome has been sequenced in our ongoing work. It will thus allow us to conduct in-depth metagenomic and transcriptomic profiling during fungal parasitism. The 2nd system is novel as it has been isolated by our group very recently from the coastal ocean. We aim to reconstruct the draft genome of this first marine model system of its kind, to initiate future in-depth studies of parasitism in microbial communities. Our overarching question is: How do parasitic (fungal) infections on phytoplankton modulate functional and metabolic capacities as well as gene expression patterns within phytoplankton–fungi–bacteria associations in aquatic environments? Given that fungal parasites are widespread in aquatic systems globally, potentially constraining aquatic productivity, commercial mass culturing but also harmful algae blooms, our study output will be relevant for science as well as industry and recreation.

• DFG Programme: Research Grants